Monday, 19 September 2011

Fall Migration 2011


Nature Notes for September 16, 2011

Migration – a time that is dear to the hearts of any birder. During migration, birds frequently turn up in places where they shouldn’t be, prompting a flurry of activity amongst birders in the know.

Fall migration is a rather protracted affair. As long as there food is available, there is no rush.

The first southbound birds are on their way by early July. These are the shorebirds which nest in the high Arctic and winter in South America. They travel huge distances, usually along a different path northbound and southbound. These paths reflect availability of the foods they need to fuel these journeys.

The first to move are the adult shorebirds. They stay in the north only as long as it takes to incubate the eggs. The young are then on their own and follow as much as a month or two later.

Right now, many birders are frequenting the Owen Point Trail at Presqu’ile Provincial Park. If there are concentrations of shorebirds anywhere in Northumberland, they are usually here. The make-up the flocks of sandpipers and plovers which stop here changes constantly from hour to hour. This is an excellent place to study shorebirds, since they can be quite close.

Next to start to move are some of the small songbirds. Yellow Warblers begin to migrate by late July. There follow waves of other warblers and such things as flycatchers, Scarlet Tanagers and Rose-breasted Grosbeaks on each good northerly wind.

Over the past three weeks, we have encountered mixed species flocks of warblers in a number of wooded locations. Although the warblers themselves can be very quiet at this season, they often travel with Black-capped Chickadees which are noisier. If you find a chickadee flock, it is worth looking it over. There may be other birds with them. Most warblers will have left by the end of this month.

The early migrating thrushes, such as Wood Thrush and Veery have mostly left. Swainson’s Thrushes and Gray-cheeked Thrushes are moving now. Hermit Thrushes will be passing soon. They are often abundant at about Thanksgiving.

Swallows have mostly left southern Ontario by now. Many winter as far south as Brazil, although many Tree Swallows only go as far as the coast of the Gulf of Mexico.

Although most Ruby-throated Hummingbirds have left, today (Sept. 13) we saw 4 during a walk in a local woods as well as two at our backyard feeder.

The first push of  sparrows and kinglets usually comes around mid-September and continues through much of October. Some will probably arrive on the next cold front.

The southern Ontario hawk watches have started up. From late August until about the first week of November, at several points along the north shores of Lakes Ontario and Erie, volunteers sit out in all weathers to record numbers and the species of hawks flying over. They also sometimes record numbers of other diurnal migrants such as Blue Jays and American Robins.

To add to the excitement of migration, the weather can blow strays our way. The winds of a Hurricane Irene or Tropical Storm Lee didn’t come close enough to bring Ontario any exotic tropical species. Although they didn’t bring anything tropical, they did ground southbound migrants and slowed migration for a several days.

During migration, the number and species of birds present in an area can vary tremendously from day to day. One never knows what the next day may bring.

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